Note 1 to entry: The spectral estimate of the mean zero crossing period, T02, is calculated as
T 02 = m 0 m 2 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm 0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9ad baGaciGabaqaamaaceGaaiGacaabaaGcbaqcaaKaamivaOWaaSbaaK qaafaacaqGWaGaaeOmaaqabaqcaaKaeyypa0JcdaGcaaqcaauaaOWa aSaaaKaaafaacaWGTbGcdaWgaaqcbauaaiaabcdaaeqaaaqcaauaai aad2gakmaaBaaajeaqbaGaaeOmaaqabaaaaaqabaaaaa@3C9B@ , where m0 and m2 are the zero and second spectral moments.